Process of preparing camphor.



UNITED STATES PATENT OFFICE.

OSSIAN CHAN, OI HELSINGFOBS, RUSSIA, AND WILHELM KEMPE, OF BERLIN, GER

MANY, ASSIGNOBS T CHEMISCHE BERLIN, -GERHANY.

EABBIK AUF ACTIEN (VOBK. E. SCHE BING), OF

PROCESS OF PREPARING .CAKPHOR.

Io Drawing.

Specification of Letters Patent.

Application filed January 11, 1909. Serial-No. 471,798.

Patented June 6, 1911.

To all whom it may concern:

Be it known that we, OSSIAN AsoHAN,

many, have invented a new and useful Improducm provementin Processes ofPreparing lamphor, of which the following is a specification.

According to this invention camphor is obtained by heating a borneol,which may be borneol or isoborneol in the liquid state,

' with or without a solvent, in the presence of a metal having theproperty of splitting off hydrogen from borneol, such as nickel, co-

&c., nickel and cobalt being particularly desirable and effective. I

The. action of the metal is catalytic.

heating the borneol with the metal the latter takes up hydrogenfrom theborneol, thereby camphor and a combination. of the meta and hydrogen,which combination decomposes readily into its constituents.

'The hydrogen escapes and the metal acts further upon unchan ed borneolin the same manner. The followingpquations, in which Me indicates acatalytic metal, illustrate the reaction The effect of the metalconsists in taking up hydrogen from; the borneol and then releasing thehydrogen; The resulting camphor is recovered by'distillation, while themetal remains as a residue and can. beused again.

If an oxid is used, for instance, cupric acid, it should be used inquantitywhich is insufficient to oxidize the borneol. The oxid isreduced to metal and the latter acts as described.

Any solvent may be used which dissolves the borneols at the temperatureat which the process iscarried on and which does not chemicallyinfluence the borneols or the metal. f

Preferably the metal is added gradually as the reaction is more completethan when a larger quantity of metal is added at the.

same time.

Examples.

1. 10 parts of isoborneol and 30 parts of paraflin are heated to 230 or240 C. in an open vessel with the addition of 2 parts of powdered nickeluntil the evolution of hydrogen ceases. The separation and purificationof the camphor is eficcted in the usual manner. The yield in purecamphor exceeds 80 per cent.

5 parts of isoborneol and one part of xylol are heated with one partofpowdered nickel for two and a half hours to 198 or 200 G. Then thetemperature is raised to 400 C. and more powdered nickel, about 0.2-0.4parts, is added until there is no further reaction. The yield of purecamphor is about 85 per cent, while without the second addition of metalthe yield would be only about 20 per cent.

3. 5 parts of isoborneol and two parts 01 petroleum are heated andstirred in a closed yessel with one part of nickel for one hour at 230C. r

4. 10 parts ofborneol, 30 parts of paraffin and one part of petroleumare heated with the addition of one part of nickel in an open vessel at240 C. When 'the evolution of hydrogen slackens 4 portions of about of apart of nickel are added one after another, a fresh portion not beingadded until the evolution of hydrogen has ceased. The yield of purecamphor is about 94.5 per cent.

5. 10 parts of borneol and 0.4 parts of xylol are heated in such manneras to allow the Sublimated portions of the borneol to return. The xyloldoes not operate here as a solvent, as it does in example 2. Nickel inthe pro ortion and the mixture heated to 200 C. until the liberation ofhydrogen ceases or slackens. Further additions of metal are made asnecessary. The yield of pure camphor is about 80 per cent.

6. To 100 kilograms of isoborneol .which of 0.8 parts is then added havebeen dissolved in 100 kilograms of paraffin oil, are added 2 kilogramsof finely divided cobalt, the mixture being then heated. The 'reactiontakes place below 200 C. and is complete in two hours. The yield of purecamphor is about 98 per cent.

7. 100 kilograms of commercial isoborneol and i kilograms of finelydivided cobalt are heated together. The evolution of hydrogen takesplace below 190 C. and is complete in five hours, the temperature beingallowed to rise at the finish to 202 C,

The catalytic metals contemplated by this application are metals whichhave the property of splitting ofi hydrogen from a borneol, Whetherborneol or isoborneol.

\Ve claim as our invention:

1. The herein described process of producing camphor from a borneolwhich consists in heating the borneol in the liquid state in thepresence of a catalytic metal which is immersed in the liquid.

2. The herein described process of producing camphor from a borneolwhich consists in heating the borneol in the liquid sists in heating theborneol in the liquid state in the presence of a solvent and a catalyticmetal which is added gradually to the liquid borneol.

In testimony whereof we hereunto set our signatures in the presence ofwitnesses.

OSSIAN ASCHAN. VVILHELM KEMPE.

Witnesses as to Ossian Aschan:

J. KUMMARN, W. LINDROTEN.

Witnesses as to \Vilhelm Kempe:

HENRY HASPER, WopDEMAR HAUPT.

Correction in Letters Patent No. 994,437.

upon the application of ()ssian It is herPhy vertified that in Letterslatvnt No. 994,437, granted June 6, 1911,

Asrhzun of Htisingful's, Rllssiil,

Kempe, i Bvriin Germany, for :in improvement in Processes of Preparinglalnphor," an error appears in the printed spvvification requiringcorrection as follows: Page 1, linv -14], the word acid should readamid: and that the said I Letters Patent should he read with hiscorreflion therein that the same may conform to the record of the casein the Patent Otfice.

Signed and sealed this 27th day of June, A. 1)., 1911.

C. U. BILLINGS,

Acting Commissioner of Patents.

[SEAL and 'ilhim

